Shaft assembly, motor rotor and motor

Abstract

A shaft assembly (1) comprises a first rotating shaft (11), a second rotating shaft (12), a first friction disc (13), a second friction disc (14) and an elastic member (15). And a part of the second rotating shaft (12) is inserted into the hollow shaft cavity (11c) of the first rotating shaft (11). The first friction disc (13) is connected with the first rotating shaft (11) in an anti-torque mode, and the second friction disc (14) is connected with the second rotating shaft (12) in an anti-torque mode. The elastic member (15) is configured to abut the first friction disc (13) against the second friction disc (14) such that the first friction disc (13) and the second friction disc (14) are capable of transmitting torque by frictional force between each other. The first friction disc (13) and the second friction disc (14) are arranged on the second rotating shaft (12) in a sleeving mode and contained in a hollow shaft cavity (11c) of the first rotating shaft (11). The invention also provides a motor rotor and a motor.

Description

Shaft assembly, motor rotor and motor Technical Field

[0001] The present application relates to the field of motors, and more particularly to a shaft assembly, a motor rotor, and a motor. Background Art

[0002] Known electric motor rotors include a rotating shaft that can be connected to the wheels of an electric vehicle. The motor transmits driving torque to the wheels via the rotating shaft, allowing the electric vehicle to travel. Accordingly, the wheels may be impacted during travel, and the impact torque from the wheels can be transmitted to the motor via the rotating shaft. However, existing rotating shafts are rigid. Under certain operating conditions, excessive impact torque can damage the motor.

[0003] Summary of the Invention

[0004] This application is made in view of the above-mentioned state of the prior art. An object of this application is to provide a shaft assembly, a motor rotor and a motor, which can overcome at least one of the disadvantages described in the above-mentioned background technology.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions.

[0006] An embodiment of the present application provides a shaft assembly, which includes: a first rotating shaft; a second rotating shaft, a portion of which is inserted into a hollow shaft cavity of the first rotating shaft; a first friction disc, which is torsionally connected to the first rotating shaft; a second friction disc, which is torsionally connected to the second rotating shaft; and an elastic member, which is configured to make the first friction disc abut against the second friction disc, so that the first friction disc and the second friction disc can transmit torque through friction between each other, and the first friction disc and the second friction disc are sleeved on the second rotating shaft and accommodated in the hollow shaft cavity of the first rotating shaft.

[0007] In an optional solution, the first friction disk and the second friction disk are coaxially arranged, the end surface of the first friction disk abuts against the end surface of the second friction disk, and a plurality of the first friction disks and a plurality of the second friction disks are alternately arranged to form a friction disk array.

[0008] In another optional solution, both end surfaces of the first friction disc are provided with friction coatings, and both ends of the friction disc array are the second friction discs.

[0009] In another optional scheme, the first rotating shaft includes a first shoulder, the second rotating shaft includes a second shoulder, the first shoulder and the second shoulder are arranged opposite to each other in the axial direction of the shaft assembly, and the first friction disk, the second friction disk and the elastic member are confined between the first shoulder and the second shoulder.

[0010] In another optional solution, the first rotating shaft is spline-connected to the first friction disc, and / or the second rotating shaft is spline-connected to the second friction disc.

[0011] In another optional scheme, the hollow shaft cavity of the first rotating shaft forms a first internal spline, the first friction disk includes a first external spline, the first internal spline cooperates with the first external spline, the second rotating shaft includes a second external spline, the second friction disk includes a second internal spline, and the second external spline cooperates with the second internal spline.

[0012] In another optional solution, the elastic member is a disc spring.

[0013] In another optional scheme, it also includes: a first bearing, which is installed between the first rotating shaft and the second rotating shaft on one axial side of the elastic member to support the first rotating shaft and the second rotating shaft in the radial direction; and a second bearing, which is installed between the first rotating shaft and the second rotating shaft on the other axial side of the elastic member to support the first rotating shaft and the second rotating shaft in the axial direction.

[0014] An embodiment of the present application further provides a motor rotor, comprising: the shaft assembly as described above; and laminations fixedly mounted on the first rotating shaft.

[0015] An embodiment of the present application further provides a motor, which includes the motor rotor as described above.

[0016] By adopting the above technical solution, the first friction disc and the second friction disc can limit the maximum torque that the shaft assembly can transmit, so that the shaft assembly has a torque protection function, thereby preventing excessive torque from damaging the shaft assembly and other components connected to the shaft assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 shows a motor rotor according to an embodiment of the present application.

[0018] FIG. 2 shows a partial cross-sectional view of the motor rotor in FIG. 1 .

[0019] FIG3 shows an exploded view of the shaft assembly of the motor rotor in FIG1 , wherein the first rotating shaft is cut away.

[0020] FIG. 4 shows a cross-sectional view of a shaft assembly of the motor rotor in FIG. 1 .

[0021] FIG. 5 is a perspective view showing a first friction disk of the shaft assembly of the motor rotor in FIG. 1 .

[0022] FIG. 6 is a perspective view showing a second friction disk of the shaft assembly of the motor rotor in FIG. 1 . DETAILED DESCRIPTION

[0023] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0024] In this application, unless otherwise specified, “connection” includes direct connection and indirect connection, “rotational connection” refers to a connection capable of relative rotation, and “torsion-resistant connection” refers to a connection capable of transmitting torque.

[0025] 1 to 6 illustrate a motor rotor according to an embodiment of the present application, particularly a motor rotor suitable for electric vehicles. Referring to FIG1 , the motor rotor may include a shaft assembly 1 , laminations 2 , and a balancing disk 3 .

[0026] It will be appreciated that the shaft assembly of the present application is not limited to use in motor rotors and can also be applied to various other situations, particularly those requiring torque limitation. Here, multiple slots can be formed in the laminations 2 to accommodate permanent magnets. Here, the balancing disc 3 is not required.

[0027] It is understood that the motor including the motor rotor of the present application can be an inner rotor motor. The motor of the present application can be used in pure electric vehicles or hybrid vehicles, and the motor can also be used in wheel hub drive systems or wheel side drive systems. However, the present application does not limit the use scenarios of the motor.

[0028] 2 to 6 , the shaft assembly 1 may include a first rotating shaft 11, a second rotating shaft 12, a plurality of first friction discs 13, a plurality of second friction discs 14, an elastic member 15, a first bearing 16, a second bearing 17, a fixed disc 18, and a retaining spring 19. Specifically, the first rotating shaft 11 may include a first internal spline 111, a first shoulder 112, and a hollow shaft cavity 11c. The first internal spline 111 and the first shoulder 112 may be formed in the hollow shaft cavity 11c. The second rotating shaft 12 may include a second external spline 121, a second shoulder 122, and a third shoulder 123. The second shoulder 122 and the third shoulder 123 may be formed on the same annular flange and arranged opposite each other. The first rotating shaft 11 may be coaxially arranged with the second rotating shaft 12, and a portion of the second rotating shaft 12 may be inserted into the hollow shaft cavity 11c of the first rotating shaft 11. The first shoulder 112 and the second shoulder 122 may be axially oppositely arranged, and the first internal spline 111 and the second external spline 121 may be located between the first shoulder 112 and the second shoulder 122 .

[0029] The first bearing 16 may be a needle roller bearing, providing radial support for the second rotating shaft 12. The first bearing 16 may be mounted on the second rotating shaft 12 and located on one axial side (the right side in FIG4 ) of the elastic member 15. The second bearing 17 may be a sliding bearing or a thrust bearing, providing axial support for the second rotating shaft 12. The second bearing 17 may be mounted on the second rotating shaft 12 and located on the other axial side (the left side in FIG4 ) of the elastic member 15. The first rotating shaft 16 may be mounted on a fixed plate 18, and a retaining spring 19 may engage with an annular groove of the first rotating shaft 11 radially inwardly of the first rotating shaft 11. Axially, the fixed plate 18 and the second bearing 17 may be constrained between the retaining spring 19 and the third shoulder 123. One end (the right end in FIG4 ) of the second bearing 17 may abut the third shoulder 123, while the other end (the left end in FIG4 ) of the second bearing abuts the fixed plate 18. Supported by the first and second bearings 16, 17, the first rotating shaft 11 can rotate relative to the second rotating shaft 12.

[0030] As shown in FIG5 , the first friction disk 13 may include a first external spline 131 and a friction coating 132. The friction coating 132 may be provided on both end surfaces of the first friction disk 13. As shown in FIG6 , the second friction disk 14 may include a second internal spline 141, which may be coaxially arranged with the first friction disk 13. Multiple first friction disks 13 and multiple second friction disks 14 may be alternately arranged to form a friction disk array, with the end surfaces of the second friction disks 14 abutting against the friction coating 132 of adjacent first friction disks 13. The first rotating shaft 11 may be fitted onto the friction disk array, such that the first internal spline 111 mates with the first external spline 131, thereby enabling the first rotating shaft 11 to rotate synchronously with the first friction disks 13. The friction disk array may be fitted onto the second rotating shaft 12, such that the second internal spline 141 mates with the second external spline 121, thereby enabling the second rotating shaft 12 to rotate synchronously with the second friction disks 14.

[0031] Furthermore, the number of second friction discs 14 can be one more than the number of first friction discs 13, so that both ends of the friction disc array are provided with second friction discs 14. In this way, the softer friction coating 132 can be covered by the second friction discs 14, preventing the friction coating 132 from contacting other components except the second friction discs 14, thereby preventing the friction coating 132 from being scratched.

[0032] The elastic member 15 may be a disc spring that fits over the second rotating shaft 12 and is arranged alongside the friction disc array. The elastic member 15 and the friction disc array are collectively constrained between the first shoulder 112 and the second shoulder 122. By adjusting the spacing between the friction disc array and the first shoulder 112, the elastic member 15 can be compressed, forcing the first and second friction discs 13 and 14 to press against each other under the pressure of the elastic member 15. Simultaneously, the third shoulder 123 presses against the second bearing 17, and the fixed disc 18 presses against the retaining spring 19.

[0033] 2 , the laminations 2 can be made of soft magnetic material, such as silicon steel sheets, and are used to carry permanent magnets. The balancing disc 3 and the laminations 2 can be mounted on the first rotating shaft 11 and can rotate synchronously with the first rotating shaft 11 .

[0034] When the motor is operating, the first rotating shaft 11 transmits driving torque to the second rotating shaft 12 through the static friction between the first and second friction discs 13, 14, causing the first and second rotating shafts 11, 12 to rotate synchronously. The second rotating shaft 12 then transmits the driving torque to the wheels via the vehicle's transmission mechanism. If the vehicle is impacted while driving, the impact torque on the wheels will be reversely transmitted to the second rotating shaft 12. Because the static friction between the first and second friction discs 13, 14 is constant, the maximum torque that can be transmitted between the first and second rotating shafts 11, 12 is also constant. If the impact torque exceeds the maximum torque that the shaft assembly 1 can transmit, the first and second friction discs 13, 14 will slide relative to each other, causing the first and second rotating shafts 11, 12 to no longer rotate synchronously. As a result, the portion of the impact torque transmitted to the first rotating shaft 11 does not exceed the maximum torque. Thus, the first and second friction discs 13, 14 limit the maximum torque that the shaft assembly 1 can transmit, providing torque protection for the shaft assembly 1, preventing excessive torque from damaging the shaft assembly 1 and other connected components.

[0035] In addition, by alternately arranging multiple first friction discs 13 and multiple second friction discs 14 into a friction disc array, the elastic component 15 only needs to apply pressure to one friction disc in the friction disc array to press all the friction discs in the friction disc array against each other, so that the shaft assembly 1 can have a smaller number of components and a more compact structure.

[0036] It should be understood that the above embodiments are merely exemplary and are not intended to limit the present application. Those skilled in the art may make various modifications and changes to the above embodiments based on the teachings of the present application without departing from the scope of the present application.

[0037] It should be understood that the number of first friction discs 13 and second friction discs 14 is not limited to multiple. For example, the shaft assembly 1 may include only one first friction disc 13 and one second friction disc 14. The plurality of first friction discs 13 and the plurality of second friction discs 14 are also not limited to being arranged in the friction disc array shown. The arrangement of the friction disc array is not limited to that shown in the embodiment. For example, one end of the friction disc array may be a first friction disc 13, and the other end may be a second friction disc 14. Alternatively, both ends of the friction disc array may be first friction discs 13.

[0038] It should be understood that the elastic member 15 is not limited to being a disc spring; for example, it may be a compression spring. The elastic member 15 is not limited to contacting a single friction disc; for example, the elastic member 15 may be located between two friction disc arrays, allowing the elastic member 15 to simultaneously apply pressure to both friction disc arrays. The elastic member 15 is not limited to applying pressure directly to the friction discs; for example, it may apply pressure indirectly to the friction discs via other possible components.

[0039] It should be understood that the maximum torque that can be transmitted by the shaft assembly 1 is adjustable. For example, the maximum torque can be adjusted by changing parameters such as the type of friction coating 132 (the friction coefficient between the first friction disc 13 and the second friction disc 14), the number of friction discs, the number of elastic components 15, the stiffness coefficient of the elastic component 15, and the compression amount of the elastic component 15.

[0040] It should be understood that the shaft assembly 1 is not limited to limiting the torque transmitted from the second rotating shaft 12 to the first rotating shaft 11 , and can also be used to limit the torque transmitted from the first rotating shaft 11 to the second rotating shaft 12 .

[0041] LIST OF REFERENCE NUMERALS 1 shaft assembly; 11 first rotating shaft; 111 first internal spline; 112 first shaft shoulder; 11c hollow shaft cavity; 12 second rotating shaft; 121 second external spline; 122 second shaft shoulder; 123 third shaft shoulder; 13 first friction disc; 131 first external spline; 132 friction coating; 14 second friction disc; 141 second internal spline; 15 elastic member; 16 first bearing; 17 second bearing; 18 fixed disc; 19 retaining spring; 2 laminations; 3 balancing disc

Claims

1. A shaft assembly, characterized in that: include: A first rotating shaft (11); A second rotating shaft (12), a portion of which is inserted into the hollow shaft cavity (11c) of the first rotating shaft (11); A first friction disc (13) which is connected to the first rotating shaft (11) in a torsion-proof manner; A second friction disc (14) which is connected to the second rotating shaft (12) in a torsion-proof manner; as well as an elastic member (15) configured to cause the first friction disk (13) to abut against the second friction disk (14), so that the first friction disk (13) and the second friction disk (14) can transmit torque through friction between each other, The first friction disc (13) and the second friction disc (14) are sleeved on the second rotating shaft (12) and accommodated in the hollow shaft cavity (11c) of the first rotating shaft (11).

2. The shaft assembly according to claim 1, characterized in that The first friction disk (13) and the second friction disk (14) are coaxially arranged, the end surface of the first friction disk (13) abuts against the end surface of the second friction disk (14), and a plurality of the first friction disks (13) and a plurality of the second friction disks (14) are alternately arranged to form a friction disk array.

3. The shaft assembly according to claim 2, characterized in that Both end surfaces of the first friction disc (13) are provided with friction coatings (132), and both ends of the friction disc array are the second friction discs (14).

4. The shaft assembly according to any one of claims 1 to 3, characterized in that The first rotating shaft (11) includes a first shoulder (112), and the second rotating shaft (12) includes a second shoulder (122). The first shoulder (112) and the second shoulder (122) are arranged opposite to each other in the axial direction of the shaft assembly (1), and the first friction disk (13), the second friction disk (14) and the elastic member (15) are restricted between the first shoulder (112) and the second shoulder (122).

5. The shaft assembly according to any one of claims 1 to 3, characterized in that The first rotating shaft (11) is spline-connected to the first friction disc (13), and / or The second rotating shaft (12) is spline-connected to the second friction disk (14).

6. The shaft assembly according to claim 5, characterized in that The hollow shaft cavity (11c) of the first rotating shaft (11) forms a first internal spline (111), the first friction disc (13) comprises a first external spline (131), and the first internal spline (111) cooperates with the first external spline (131). The second rotating shaft (12) includes a second external spline (121), the second friction disk (14) includes a second internal spline (141), and the second external spline (121) and the second internal spline (141) are matched.

7. The shaft assembly according to any one of claims 1 to 3, characterized in that The elastic component (15) is a disc spring.

8. The shaft assembly according to any one of claims 1 to 3, characterized in that Also includes: a first bearing (16) installed between the first rotating shaft (11) and the second rotating shaft (12) on one axial side of the elastic member (15) to support the first rotating shaft (11) and the second rotating shaft (12) in a radial direction; and A second bearing (17) is installed between the first rotating shaft (11) and the second rotating shaft (12) on the other axial side of the elastic member (15) to support the first rotating shaft (11) and the second rotating shaft (12) in the axial direction.

9. A motor rotor, characterized in that: include: The shaft assembly (1) according to any one of claims 1 to 8; as well as The lamination (2) is fixedly mounted on the first rotating shaft (11).

10. A motor, characterized in that: Comprising the motor rotor as described in claim 9.

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